The present invention generally relates to an inflator for an air bag or cushion and, more specifically, to the type of inflator known as a hybrid inflator.
it is known that if the early inflation rate of an air bag is too high, the resulting deployment forces can contribute to the possible injury of an occupant who is out of the normal seated position. If, however, the air bag inflation rate is maintained at a relatively low rate, primarily to reduce such deployment forces, full deployment of the air bag may not be timely achieved, and therefore the air bag may not provide the desired level of safety for the vehicle occupants.
It has for some time been appreciated that the goal of air bag design is to provide an inflator which initially has a relatively low or soft inflation rate (for a relatively few milliseconds) primarily to protect the out-of-position passenger, such as a standing child, who would be subject to large deployment forces, and thereafter to rapidly increase the inflation rate of the air bag to cause rapid and full inflation.
Therefore, a need has been created for an economical, reliable and effective inflation device which can achieve the above-described staged, variable inflation of an air bag. The inflation device of the present invention meets this need.